1. Field
This invention relates to methods and devices for identification and non-intrusive communication between a server node and several client nodes within a real time switched network.
2. Description the Related Art
A network of “switch fabric” type is based on a switched architecture, that is, the terminal equipment items responsible for the transmission and reception of data are organized around switches responsible for the transport of these data, to N inputs and N outputs. Communication is performed by the sending and reception of packets, the latter being sent out in parallel.
More generally, the invention relates, in a network for processing of data in real time comprising at least one server and at least one client, to the principles governing the communication of diagnostic data between these components of the network so as to be non-intrusive on real time communication also circulating over this same network.
The invention applies in particular in a network for simulation of components of an aircraft in real time, where a diagnosis of these components must be made without disrupting the simulation network.
Simulation of components of an aircraft is used to ensure the development and integration of on-board electronic and computer systems in aircraft, in particular prior to the first flight.
The simulation architecture comprises a plurality of terminals also called nodes of the network, each of these terminals being able to perform simulation calculations or constituting the electronic interface with the real environment, making it possible to verify the functioning of the real equipment items of the aircraft. In this way, this architecture comprises in particular a simulation terminal able to transmit data according to a synchronous sequence in accordance with a request/response principle.
Network nodes are made up of simulation computers and of electronic interface input/output cards.
Data exchange between the various nodes of the network is carried out on a specific UDP (acronym for “User Datagram Protocol” in English terminology) port and in real time, that is, the simulation of the performances of equipment items is carried out at the speed of their actual development.
In order to carry out diagnoses on such a network architecture, there can be connected to the network at any moment a diagnostic equipment item able to identify malfunctions of various nodes of the system.
Nonetheless, without a specific phase of learning the topology of the network, exchanges of messages generate an additional traffic on the network between the diagnostic equipment item and the various nodes of the network. The messages exchanged are typically of the ARP (acronym for “Address Resolution Protocol” in English terminology) type.
Such a use has the drawback that a great number of ARP messages between the diagnostic equipment item and the network nodes are transmitted, which disrupts the execution of the simulation in real time.